Bumped version to 1.7.4.
Bumped version to 1.7.4.

tw4452852/the_platinum_searcher,cmars/tools,aeruder/the_platinum_searcher,cmars/tools,monochromegane/the_platinum_searcher,syohex/the_platinum_searcher,cmars/tools,DaSea/the_platinum_searcher,thomasf/the_platinum_searcher,cmars/tools,yuya-takeyama/the_platinum_searcher